Public Class Form1
  Private Sub Label1_TextChanged(…) Handles Label1.TextChanged
    showFiles(Me.Label1.Text)
  End Sub
 
  Private Sub showFiles(ByVal strSelectedPath As String)
    MsgBox("showFiles(" & strSelectedPath & ")")
  End Sub
End Class

Public Class FolderControl
  Private Sub FolderControl_Load() Handles Me.Load
    Me.TreeView1.Nodes.Add("C:")
    Me.TreeView1.Nodes(0).Nodes.Add("Test1")
    Me.TreeView1.Nodes(0).Nodes.Item(0).Nodes.Add("Test1_2")
    Me.TreeView1.Nodes(0).Nodes.Add("Test2")
    Me.TreeView1.Nodes(0).Expand
  End Sub
 
  Private Sub TreeView1_AfterSelect(…) Handles TreeView1.AfterSelect
    Me.ParentForm.Controls.Find("Label1",False).First.Text = _
      Me.TreeView1.SelectedNode.Text
  End Sub
End Class

Public Class ucTree
 
    'Klasse als Event-Parameter
    Public Class TreeNodeClickedEventArgs
        Inherits EventArgs
        Private _path As String = ""
 
        Public Sub New(path As String)
            _path = path
        End Sub
 
        Public ReadOnly Property Path As String
            Get
                Return _path
            End Get
        End Property
    End Class
 
    Dim WithEvents trv As New TreeView With {.Parent = Me}
 
    'Ereignis
    Public Event TreeNode_Clicked(sender As Object, _
       e As TreeNodeClickedEventArgs)
 
 
    Private Sub ucTree_Load(sender As System.Object, _
        e As System.EventArgs) Handles MyBase.Load
        'testdaten
        Dim tn As TreeNode = trv.Nodes.Add("Node1")
        tn.Nodes.Add("Subnode1")
        tn = trv.Nodes.Add("Node2")
        tn.Nodes.Add("Subnode2")
    End Sub
 
 
    Private Sub trv_NodeMouseClick(sender As Object, _
        e As System.Windows.Forms.TreeNodeMouseClickEventArgs) _
        Handles trv.NodeMouseClick
 
        If e.Button = Windows.Forms.MouseButtons.Right Then
            'Ereignis auslösen, Pfad als Parameter
            RaiseEvent TreeNode_Clicked _
                (Me, New TreeNodeClickedEventArgs(e.Node.Text))
        End If
    End Sub
 
End Class

Public Class frmTree
 
    'das UserControl
    Dim WithEvents uct As New ucTree With {.Parent = Me}
 
    'Der Eventhandler
    Private Sub uct_TreeNode_Clicked(sender As Object, _
        e As ucTree.TreeNodeClickedEventArgs) Handles uct.TreeNode_Clicked
        MsgBox(e.Path)
    End Sub
 
End Class